This paper investigates relationships between neighborhoods’ urban form, roadway characteristics, traffic collisions, and fatalities in the Philadelphia region. Particular attention is given to neighborhood population density, the most commonly used and discussed measure of urban form and a measure that is directly related to the most commonly used traffic safety statistic, fatalities per 100,000 people. A better understanding of whether denser neighborhoods correlate with higher or lower traffic fatalities could shed light on the likely public health effects of promoting compact cities. Better understanding of the factors that promote neighborhood traffic safety could also help households make more informed decisions about the tradeoffs between different types of neighborhoods.